JP7455192B2 - Method for producing protein-containing foods - Google Patents

Description

The invention particularly provides more than 50% by weight, preferably 60% by weight, based on vegetable proteins, insect proteins, cellular proteins, such as yeast, bacteria, microalgae, molds, or mixtures of different proteins. A novel foamed and textured protein-rich food product obtained from at least one dry raw material having a protein content of ˜90% by weight. Such food products are also referred to below as protein-containing texturates and, according to a preferred embodiment, as meat substitute products (“meat substitutes”). The invention also relates to a method of producing such novel foamed and textured protein-rich food products.

Novel foods such as meat substitutes based on plant proteins are becoming increasingly important as part of sustainability trends. Traditional methods for their manufacture usually involve the following steps:
- Weighing/feeding raw materials;
- mixing the raw materials;
- a pre-processing step (optional);
- an extrusion step, in particular using a cooling die;
- Includes a cutting step.

The main challenge for the acceptance of alternative meat products is to match their texture, their color and their organoleptic properties (crispness) as closely as possible to the corresponding properties of real meat products. However, substitute meat products produced using known and commercially available methods differ significantly from real meat in their texture, their color, and their crispness. This applies to the fibrous quality as well as to the tenderness or juiciness of the meat substitutes currently on the market. Generally, each new food product faces the same challenges with respect to texture, color, and crispness in order to be accepted by consumers.

The reason for the above difference is that thermal energy (heating the cooling water in the extruder housing and cooling die, or introducing steam into the system) and mechanical energy (specific mechanical energy input) are introduced. It involves a very high energy process. However, the increased supply of energy in this process inevitably results in stronger texturing, which has a negative impact on the crispness or softness of the final product and causes the product to have rubbery properties. Become.

Due to the high moisture content of the product, it is also necessary to freeze the extrudate (final product) following the extrusion process. The freezing process modifies the texture to allow inclusion of the second phase and thus the crispness and juiciness of the extrudate are advantageously influenced. Instead of freezing, the extrudates are cooked and/or subjected to vacuum coating. Both method steps allow for the inclusion of a second phase, but are also very complex.

EP 1 059 040 A1 describes a method in which a protein-rich material is processed in an extruder and cooled to a temperature below 100° C. by drawing through a cooling die placed at the end of the extruder.

WO 96/34539 A1 describes a method in which a protein-rich material is processed in an extruder and cooled by drawing it through a cooling die located at the end of the extruder. The product thus obtained does not closely resemble real meat.

WO2012/158023A1 describes a method for producing soy protein extrudates from aqueous soy protein compositions by extrusion. Compositions having at least 50% water by weight are cooled to below the boiling point of water under prevailing ambient conditions (i.e., 100° C. at normal pressure) as they exit the extruder. The product thus obtained has a relatively continuous pore structure, the properties of which can be modified by injecting the corresponding liquid into these pores.

In this method, the pore structure of the extruded product resulting from the formation of water vapor as it exits the extruder is purely random. Additionally, pore variation depends on the protein used, its concentration, and process controls. However, the large number of parameters and their interrelationships are complex, and constant product quality is guaranteed only in very narrow configurations. Therefore, pore quality can only be moderately controlled through process control. It is not possible to influence the formation of micropores in a targeted manner.

The aim of the invention is to overcome the drawbacks of the prior art. In particular, protein-rich foamed foods with as homogeneous a pore quality as possible and acceptable texture and color properties can be manufactured in a controlled manner to improve, among other things, the crispness and softness of the product. It should be manufacturable. Additionally, other phases should also be able to be included in the product without the freezing, cooking, or vacuum coating method steps required in the prior art. The energy required for manufacturing should also be reduced as much as possible.

This object is achieved by obtaining a protein-rich foamed product and by inventing a method for producing it according to the independent claims.

The method according to the invention for producing a protein-containing foamed food product comprises the following steps:
a) metering the raw materials into the extruder, wherein at least one raw material is a protein, preferably a vegetable protein, an insect protein, a cellular protein, e.g. a cellular protein such as yeast, bacteria, microalgae, molds, etc. , or a mixture of different proteins, wherein the protein content in the dry raw material is more than 50%, particularly preferably in the range from 60% to 90%, and the starch content in the dry raw material is less than or equal to 50%, preferably 5-30% and the raw material comprises at least one component having a fiber content;
b) mixing the raw materials in an extruder to produce a mixture;
c) extruding the mixture to produce an extrudate, the solids content of the extrudate being in the range 20% to 60%, preferably in the range 30% to 50%;
d) drawing the extrudate from the extruder through a cooling die while cooling the extrudate to a temperature below 100°C; The pores are controlled in the extruder by supplying gas so as to result in a foamed product having a protein content and a liquid content, preferably water content, of 45-70% by weight, preferably 55-65% by weight. It is formed using a method.

According to the invention, controlled pore formation in foamed food products, preferably meat substitute products, and the associated adaptation of product properties to those of real meat, is achieved by supplying gas to the extruder during the extrusion process. It was found that this could be achieved. In contrast to the method of WO 2012/158023A1, a specific control of the pore formation process, in particular of at least partially interconnected pores, is possible by supplying a specific amount of gas. Therefore, pore formation is controlled by the method according to the invention.

It is known to supply gas during the production of baked goods or snack products or similar food products such as breakfast cereals. In US-6,207,214, when manufacturing Korean baked goods by extrusion, CO ₂ is introduced into the extruder. However, these are fundamentally different products from the protein-rich foamed food products concerned here, preferably meat substitute products with a high protein content, which differ significantly in terms of their properties.

According to the invention, gas is understood to mean a substance that is gaseous under normal conditions (1 bar, 20° C.). Examples of gases that can be used according to the invention are CO ₂ , N ₂ , N ₂ O, NH ₃ or SO ₂ .

According to the invention, gas is supplied to the extruder in order to achieve controlled pore formation in the treated material. According to the invention, this supply:
- by introducing gas into the extruder via the feed port, and/or - by releasing gas in the extruder by reaction of a gas-forming compound added as raw material with a gas-releasing compound added as raw material. be able to.

According to one embodiment of the invention, the raw material may thus contain at least one gas-forming compound and at least one gas-releasing compound. The gas is formed during extrusion in step c) by a chemical reaction between the gas-forming compound and the gas-releasing compound.

According to the invention, gas-forming compounds are understood to mean substances that react with suitable gas-releasing compounds to release gas in the extruder under the prevailing conditions. Typical examples of gas-forming compounds are physiologically acceptable salts such as carbonates or bicarbonates, for example sodium carbonate (Na ₂ CO ₃ ), potassium carbonate (K ₂ CO ₃ ), or sodium bicarbonate. (NaHCO ₃ ) and CO ₂ can be released from these salts. Another example is Staghorn salt (a mixture of ammonium bicarbonate (NH ₄ HCO ₃ ), ammonium carbonate ((NH ₄ ) ₂ CO ₃ ), and ammonium carbamate (NH ₄ CO ₂ NH ₂ )). , NH ₃ and CO ₂ gases can be released from this salt.

Gas (particularly preferably CO ₂ ) can be released from these gas-forming compounds by reaction using the gas-releasing compounds. This can be any compound that reacts with a corresponding gas-forming compound to form a gas. The gas releasing compound is usually a physiologically acceptable acid. The acid can be, for example, citric acid, a phosphoric acid compound such as disodium dihydrogen phosphate or monocalcium orthophosphate, tartaric acid or one of its salts (for example potassium sodium tartrate (Rochelle salt)), malic acid, It can be fumaric acid, adipic acid, or glucono delta-lactone. Acids may be used as free acids or in the form of their anhydrides or salts.

According to the invention, the gas to be fed is preferably produced in this embodiment by an acid-base reaction in an extruder. For example, carbon dioxide (CO ₂ ) gas can be produced by the reaction of sodium bicarbonate (NaHCO ₃ ) salt and citric acid (C ₆ H ₈ O ₇ ).

The texture of the extrudates can be influenced in a targeted manner by appropriate selection of gas-forming and gas-releasing compounds, preferably salts and acids, and their weight proportions. In this way, it is possible to include the second phase and possibly further phases in a controlled manner. This ensures improved absorption of water or flavoring ingredients such as broth, fats or oils, which has an advantageous effect on the crunching behavior of the extrudates.

Gas-forming and gas-releasing compounds, preferably salts and acids, can be added to or added to the dry raw materials metered into the extruder. Alternatively, the acid can be fed separately to the extruder in liquid form.

The gas-forming and gas-releasing compounds preferably amount to 0.1% to 5% by weight, particularly preferably 0.2% to 1.5% by weight, based on the total weight of all raw materials metered into the extruder. It is present together in the raw material in a proportion of 6% by weight. Depending on the stoichiometry of the corresponding reaction, the mass ratio of gas-forming compound to gas-releasing compound, preferably salt to acid, is preferably 1: in order to achieve the most complete gas release possible. It ranges from 1 to 6:1.

According to a further embodiment of the invention, gas is supplied to the extruder by introducing the gas into the extruder.

According to this embodiment of the invention, therefore, at least one gas is introduced into the extrudate during extrusion in step c). This is usually done through the feed port of the extruder, which is connected to a gas container (e.g. a pressure bottle) and allows the controlled introduction of gas into the extruder (e.g. via a valve). be exposed.

Examples of gases that can be used according to the invention in this embodiment are _CO2 , _N2 , _N2O , _NH3 or _SO2 , preferably _CO2 or _N2 . The gas may be introduced in gaseous form or as a liquefied gas.

The introduction of gas also ensures controlled pore formation. The use of _SO2 can lead to the formation of disulfide bridges with proteins contained in the raw materials, resulting in further effects on the texture of the product. The gas may, for example, be introduced into the extruder in an amount of 0.01 to 5% by weight, preferably 0.05 to 2.5% by weight, based on the total weight of the raw materials metered into the extruder. . For example, the gas may also contain 0.5 to 3.0 g (grams), preferably 1.0 to 1.5 g, of gas per kg (kilogram) of raw material extruded in the extruder after the raw material leaves the extruder. may be introduced in amounts.

According to the invention, the gas is preferably introduced into the extruder at a pressure in the range from 10 to 50 bar, preferably from 15 to 30 bar. According to the invention, the extrudate has a temperature in the range from 80 to 180°C, preferably from 120 to 170°C, particularly preferably from 130 to 160°C, at the location of the inlet for the gas in the extruder.

According to the invention, the raw materials are metered into an extruder, and at least one raw material is a protein, preferably a vegetable protein, an insect protein, a cellular protein, e.g. protein, or a mixture of different proteins. The term "at least one raw material is a protein" also encompasses embodiments where the raw material contains protein or constitutes a protein source.

Plants are preferably used as a protein source, for example legumes (eg legumes such as peas, lupine or fava beans), cereals (eg wheat, soybean, rapeseed or sunflower), or algae. However, animal proteins such as milk proteins or whey proteins, or proteins from muscle meat or connective tissue may also be used. However, according to the invention it is preferred to produce a product that is free of animal proteins. For example, insect proteins, cellular proteins, especially cellular proteins from yeast, bacteria, microalgae, molds, etc. may also be used.

According to the invention, the raw material preferably comprises at least one component with a fiber content. Mention may be made, for example, of pea fibers with a fiber content of at least 50% of their dry weight.

The protein-containing raw material is fed into the extruder together with the liquid. As mentioned above, this is at least one protein-containing raw material as described above and one liquid as described above. Optionally, gas-forming and gas-releasing compounds may be added if the gas is to be provided by releasing gas through chemical reaction of these compounds.

Oil-containing substances such as water, broth, and/or oil-containing flavoring ingredients may be used as the liquid.

According to the invention, the protein-containing raw material and the liquid are metered in such a ratio that the protein content in the dry raw material is greater than 50%, particularly preferably in the range from 60% to 90%. The starch content (carbohydrate content) in the dry raw material is therefore below 50%, preferably in the range from 5 to 30%.

Additionally, additives commonly used in the production of meat substitute products may be added. For example, salts such as sodium chloride, fats, oils or other lipids may be added, preferably in an amount of 0.1 to 10% by weight, relative to the total weight of all dry raw materials.

The method according to the invention is used for the production of wet textures. Wet texture is understood to mean an extrudate in which the solids content of the extrudate in step c) is in the range from 20% to 60%, preferably in the range from 30% to 50%. The remaining 80-20%, preferably 70-50%, is one of the liquids mentioned above, preferably water. In the case of wet textures, it has proven advantageous if the protein content in the dry raw material is more than 50%, particularly preferably in the range from 60% to 90%.

According to the invention, commercially available extruders used in the prior art for the production of the corresponding food products can be used. Examples include the extruders mentioned in WO 2012/158023A1 or Buehler's extruders, especially twin screw extruders. Such an extruder preferably has an L/D ratio (length to diameter) in the range from 20 to 60, preferably from 25 to 50, particularly preferably from 25 to 40. According to the invention, the extruder is preferably operated at 300-500 rpm, particularly preferably 350-400 rpm.

Pre-weighed raw materials are metered into the first part of the extruder. Alternatively, different raw materials can be added to the extruder sequentially in different portions.

One or more raw materials may be pretreated prior to step a) of metering into the extruder. In this way, the residence time of the protein matrix in the process can be influenced. It is currently assumed that a longer residence time leads to an improved fiber structure, since a greater number of crosslinked filaments are generated during extrusion. According to the invention, the residence time in the pretreatment is preferably 3 to 600 seconds, particularly preferably 3 to 60 seconds, particularly preferably 5 to 15 seconds.

The metered raw materials are mixed with each other in an extruder, thereby forming a liquid, preferably aqueous, protein composition. The mixer may be configured as a high speed mixer. It may have water and steam supply lines. The extruder may have a water supply line and optionally a steam supply line.

A liquid, preferably aqueous, protein composition is processed in an extruder. Here, the composition is heated to a temperature above the denaturation temperature of the protein, preferably in the range from 80 to 180°C, more preferably from 120 to 160°C, particularly preferably from 130 to 150°C, depending on the protein used. heated. The extruder housing is preferably temperature controlled. The composition is kneaded under pressure (usually 1 to 60 bar, preferably 8 to 20 bar, particularly preferably 10 to 15 bar) to form a homogeneous mixture. This typically involves an energy input of 10-120 Wh/kg, preferably 15-30 Wh/kg.

The method according to the invention can in principle be operated with a throughput in the range from 10 to 600 kg/h. According to the invention, the process is carried out with a throughput of 10 to 60 kg/h, preferably 20 to 50 kg/h, particularly preferably 30 to 40 kg/h, or alternatively 100 to 600 kg/h, preferably 300 to 600 kg/h, Particular preference is given to carrying out with a throughput of 400 to 550 kg/h, and the material in the extruder preferably has a retention time of at least 2 minutes, preferably at least 4 minutes.

The gases introduced by an embodiment of the method according to the invention may be introduced at different locations in the extruder, either near the inlet region, in the intermediate region, or in the outlet region. According to the invention, the feed inlet for the gas is preferably in the vicinity of the cooling die (i.e. at the extruder outlet), preferably in the last third of the length of the extruder before the cooling die, in particular It is preferably located in the part of the extruder located in the last quarter of the length of the extruder before the cooling die.

According to a preferred embodiment of the invention, instead of the conventional conveying element, a kneading and/or mixing element for intensively mixing the introduced gas with the extrudate and dispersing the gas in the extrudate is provided. It is located at the gas supply port inside the aircraft. Such elements are known. By way of example, mention may be made of so-called Igel screws, barrier screws, T-elements (for example from Extricom). These give a high distribution and dispersive mixing effect while at the same time low energy input to the product.

The invention therefore also provides a gas supply unit and a kneading and/or mixing element provided at the location of the gas supply unit for producing a protein-containing food product, preferably by the method of the invention as described herein. The invention relates to the use of an extruder comprising:

After the extrusion in step c), in a further step d) the extrudate is drawn from the extruder through a cooling die and under normal conditions brings the extrudate to a temperature below the boiling point of water, ie below 100°C. Cooling dies for extruders are well known. According to the invention, the extrudate is preferably cooled to a temperature in the range of 50-90°C.

The resulting foamed product has a protein content in the range 15-30%, preferably 19-23% by weight, and a liquid content, preferably water content, in the range 45-70%, preferably 55-65% by weight. have Preferably, the resulting foamed product has uniformly distributed pores of about 0.1 to 1 mm diameter with a narrow size distribution, and more preferably additionally uniformly distributed closed cavities.

According to a preferred embodiment, in order to achieve improved wall slippage in the cooling die and thus easier process control, e.g. and injecting oil into the distribution body of the extruder and/or into the cooling die itself in a proportion in the range from 1% to 10%, preferably in the range from 2% to 6%, particularly preferably in the range from 3% to 4%. be able to. For example, edible oils such as sunflower oil are used. One or more supply lines for additives, for example oils, fats, or calcium and/or alginate, are provided, whereby this supply line is advantageously located near the cooling die or It opens to the inside. Preferably, the feed line transports the additive into the extrudate.

The combination of calcium compounds and alginate can affect juiciness as it causes at least partial gelation of the product. Calcium compound and alginate can be added at different times or at the same time, and can also be added as a mixture. It is advantageous to add the calcium compound and alginate after the gas has been added, but before the extruded product has solidified.

After leaving the extruder, the extrudate can be cut into suitable shapes and sizes in a further step in a known manner, in particular to make the pores at least partially accessible from the outside.

The dispersed gas fraction and bubble size/size distribution have a quantitative effect on textural properties (e.g. "crisp and chew properties" such as softness, hardness, chewability, etc.) and, in turn, influence the structural parameters in the dispersed gas phase. These sensory properties can be adapted by adapting the As the gas fraction increases (up to a matrix-specific critical value) and the bubble size decreases (gas volume fraction remains constant), the structure is assumed to stiffen. This leads to an increase in hardness, expressed as the maximum force required to initiate structural failure during cutting/biting, but affects chewability as the amount of deformation required for failure increases. The foaming of the matrix therefore extends the range of means for adapting meat-like crunch/chew properties, for example from chicken to beef.

In contrast to the methods described in the prior art, for example for producing bread dough or snack products, the method according to the invention is carried out at temperatures at which denaturation of the proteins present in the raw materials occurs. The process according to the invention is also carried out at temperatures at which the starch crystals melt ("gelatinization"). According to the invention, temperatures in the extruder are applied, for example, in the range from 80°C to 180°C, preferably in the range from 120°C to 170°C, particularly preferably in the range from 130 to 160°C. In methods described in the art, lower temperatures are used to avoid denaturation or "gelatinization" of the protein. Also, bread doughs are typically not extruded through a cooling die, but rather subjected to a subsequent baking process to solidify their structure.

According to the invention, protein-containing foamed foods (i.e. foods with a protein content of more than 50% of their dry weight) correspond more to meat products than protein-containing foods from the prior art, e.g. with respect to their texture, color and crispness. ) can be manufactured. However, other foamed protein-containing food products (with a protein content of more than 50% of dry weight) can also be provided according to the invention. For example, it is possible to obtain a mousse-like food product with greater structural stability than real mousse.

A particularly advantageous protein-containing food product can be obtained by the process according to the invention, which involves introducing a gas into the extrudate.

Protein-containing food products produced by the method according to the invention using the addition of gas-forming and gas-releasing substances typically have a maximum overrun of 150%, preferably 100% (i.e. extruder exit height (with a height greater than It has holes.

Protein-containing food products produced according to the invention using the introduction of gas typically have a maximum overrun of 150%, preferably 100% (i.e., a height above the extruder exit height; The volume of the sample is thus increased) and/or has uniformly distributed pores of diameter approximately 0.1-0.3 mm with a narrow size distribution.

According to the invention, a "narrow size distribution" means that the diameter of at least 80%, preferably at least 90% of the individual pores deviates from the abovementioned values by only 0.1 to 10%, preferably 0. This means 2 to 5%.

The average area of the pores or the cavities formed by several interconnected pores is 21'292 ± 36'110 μm2, and the average minimum diameter and average maximum diameter are 125 ± 73 μm and 125 ± 73 μm ^, respectively. It is 239±153 μm.

Pores and pore distribution can be analyzed by microscopy or X-ray tomography, as is known in the art.

The color of protein-containing foamed food products produced according to the invention is significantly lighter than the color of equivalent protein-containing food products produced without foaming. Color is measured using a conventional spectrophotometer at SCI (including specular reflection). The sample to be measured must have a sufficiently thick layer so that no light is transmitted through the sample material and the measurement port is completely covered with the sample material. Reflection measurements are performed in daylight (D65) with a d/8° measurement geometry. L ^* , a ^* , b ^* , and C ^* values are determined. L ^* values indicate lightness, and positive a ^* values indicate red color. A positive b ^* value represents the yellowness of the material. Saturation is represented by the C ^* value.

The (synthetic) protein-containing food product produced according to the invention is distinguished by an L ^* value that deviates from the L ^* value of the reference meat product by no more than 20%, preferably no more than 15%. Depending on the field of application, the meat product used as reference is selected from known meat products such as chicken, pork, beef or lamb. Note that if the L ^* value alone is similar to the L ^* value of the reference meat product, the food will not be a meat substitute product. To qualify as a meat substitute product, a food product must also meet the textural and porosity conditions described herein. For example, a snack product with an L ^* value similar to that of the reference chicken product may be considered ^an alternative meat product for the express reason that the texture and porosity of the snack product is not comparable to that of the reference chicken product. Not eligible.

The protein-containing foamed food products produced according to the invention are further characterized by a fibrous, porous, longitudinally oriented cross-linked structure. When dry, the individual layers do not separate from each other, but remain bonded to each other.

The protein-containing foamed food products produced according to the invention are further distinguished by a porous structure with closed cavities and with a uniform distribution of cavities. The cavities preferably have a diameter of 100-300 μm with a normal deviation in the range 50-70%.

The invention therefore also provides a protein-containing foamed food product, preferably obtainable by the method according to the invention as described herein, in which the L ^* value of the food product deviates from the L ^* value of the meat product. 20% or less, preferably 15% or less.

The protein-containing foam food product according to the invention preferably has a fibrous, porous and longitudinally oriented crosslinked structure.

The invention also provides a protein-containing foamed food product, preferably obtainable by the method according to the invention as described herein, in which the L ^* value of the food product is preferably derived from the L ^* value of the meat product. the deviation is not more than 20%, preferably not more than 15%, the food product has a porous structure with closed cavities and the cavities are uniformly distributed, and the cavities are preferably 50-70% It relates to a protein-containing foamed food product having a diameter with a normal deviation in the range 100-300 μm.

The protein-containing foamed food product according to the invention is characterized by a specific texture. These products have longitudinally oriented layers arranged around a central cavity. Preferably, these layers are not arranged very closely next to each other, but are interrupted by small cavities. This results in a porous structure. According to a preferred embodiment of the invention, the foamed food product of the invention, when dried, exhibits clearly recognizable individual layers that are not separated from each other but are bonded to each other at certain points. The fibrous structure is longitudinally oriented, corresponding to the die used in the manufacturing process.

The protein-containing foamed food according to the present invention has a strength in the longitudinal direction (F _L ) of 10 to 50 N, preferably 15 to 40 N, more preferably 12 to 20 N, and a transverse direction (F _T ) of 10 to 90 N, It is characterized by the maximum force (peak force) required to break the structure of the product when cutting or biting off, preferably in the range 15-70N, more preferably 15-50N.

Maximum force can be determined using a Warnzer-Brazler blade set with a "V" slotted blade (https://textureanalysis-professionals.blogspot.com/2014/12/texture-analysis-in-act ion -blade-set.html). This analysis helps quantify the cutting or crisping characteristics of the product. All texture analysis measurements are performed at room temperature of 25°C.

The blade set includes a reversible blade, a slotted blade insert, and a blade holder. A reversible blade has a knife edge on one end and a flat guillotine edge on the other end. During operation, the blade is held securely by a blade holder that screws directly onto the texture analyzer. The slotted blade insert is placed directly on the platform and acts as a guide for the blade while providing support for the product.

The protein-containing foamed food product according to the invention can be cut not only in the transverse direction (perpendicular to the flow direction of the extruded strands) (F _T ), but also parallel to the flow direction of the extruded strands (F _L ). are also cut, and the maximum force (peak force) for each can be determined using the previous Warnzer-Brazler blade set and can be expressed in Newtons (N).

In contrast to bread dough, the protein-containing foamed food products according to the invention exhibit significant anisotropy with respect to their mechanical properties, ie their F _T and F _L values. The anisotropy index can be calculated from the ratio of F _T and F _L values (A=F _T /F _L ) and represents a measure of the fibrous nature of the product.

Generally, in the case of protein-containing foamed foods according to the invention, the F _L value is lower than their F _T value, so that the protein-containing foamed foodstuffs according to the invention are >1, preferably >2, particularly preferably between 2 and It exhibits an anisotropy index of 2.5, even more particularly preferably 2.1 to 2.4. The protein-containing foamed food product according to the invention can be used as a base (matrix) for cell culture. Because its porous structure has a beneficial effect on cell growth, the protein-containing foamed food also contains nutrients or other ingredients suitable for cell culture, which can be delivered to the pores of the foamed food, for example. Because you will get it.

Preferably, the outer surface of the protein-containing foam food product is open in at least some areas, so that at least some of the pores are accessible.

The protein-containing food according to the invention can also be used as animal feed. In the post-extrusion process, the pores of the extrudate are enriched with additives common in animal feed, such as nutrients and/or flavors.

The present invention also relates to a cooling die having one or more feed lines for enriching the extrudate with additives such as nutrients, flavors, oils, and/or fats before it exits the cooling die.

The invention will be explained in more detail below on the basis of some non-limiting exemplary embodiments.

A. Preparation of Wet Textures The extruders described above, such as Buehler's PolyTwin BCTL-42 32L/D extruder, can be used as extruders.

Depending on the protein used, the extruder housing is set at a temperature, for example, in the range from 80°C to 180°C, preferably in the range from 120°C to 160°C, particularly preferably in the range from 130 to 150°C. In this case, the extruder housing can be set at different temperatures, for example 120° C. in the inlet region, 160° C. in the middle region and 140° C. in the outlet region.

The protein content in the dry raw material is more than 50%, particularly preferably in the range from 60% to 90%. For example, vegetable proteins such as legume or wheat proteins can be used as proteins, but also animal proteins such as milk proteins. Furthermore, insect or cellular proteins, in particular cellular proteins from yeast, bacteria, microalgae, molds, etc., or mixtures of different proteins can be used. The extrudate may contain water, broth, and/or oil-containing flavor ingredients as liquids. The liquid particularly preferably has a temperature near its boiling point.

The dry raw materials are metered into an extruder, where they are kneaded together with the liquid under pressure and temperature action (for example in the range from 1 bar to 60 bar, preferably from 8 bar to 20 bar, particularly preferably from 10 bar to 15 bar). to obtain a homogeneous composition. During the course of this method, the proteins unwind and align into cross-linked filaments as they enter the cooling die. The composition is heated during the process from ambient temperature to the temperature necessary for protein denaturation. For example, for soy protein this is approximately 140°C. A processing temperature of 120° C. has proven suitable for pea or sunflower proteins. Depending on the quality of the raw materials, a temperature of 160°C may be required.

As the extrudate exits the extruder, it passes through a cooling device, such as a cooling die. This involves bringing the composition to a temperature level below the boiling point typical at ambient conditions, for example in the range of 50°C to 90°C. To achieve this, cooling water with a temperature in the range 40°C to 90°C, preferably 50°C to 70°C is used in the cooling die.

To achieve improved wall slippage in the cooling die and thus easier process control, e.g. 1% to 10% relative to the total weight of all raw materials metered into the extruder The distribution body of the extruder and/or the cooling die itself can be injected with oil in a proportion in the range , preferably in the range 2% to 6%, particularly preferably in the range 3% to 4%. For example, edible oils such as sunflower oil are used.

The extrudate may weigh in the range 10 kg/h to 600 kg/h, such as in the range 10 to 60 kg/h, preferably in the range 20 kg/h to 50 kg/h, more preferably in the range 30 kg/h to 40 kg/h, or It is passed through the extruder at a throughput in the range from 100 to 600 kg/h, preferably from 300 to 600 kg/h, particularly preferably from 400 to 550 kg/h. The specific mechanical energy input introduced by the extruder may range from 10 Wh/kg to 120 Wh/kg, preferably from 15 Wh/kg to 30 Wh/kg, depending entirely on the raw material mixture. do. Preferably, the holding time (residence time) is at least 2 minutes, preferably at least 4 minutes.

If (micro)pore formation is caused by a chemical reaction, salts and acids should preferably be added to the dry raw materials. Possible salts are, for example, sodium bicarbonate or potassium bicarbonate. Citric acid, tartaric acid or its salts, and glucono delta-lactone can be used as acids. Additionally, phosphate-containing acid carriers such as disodium dihydrogen diphosphate or monocalcium orthophosphate are suitable. Here, the mixing ratio can be changed to control the amount of gas released. A salt to acid ratio in the range 1:1 to 6:1 is preferred. _CO2 or _NH3 is preferably released as a pore-forming gas.

Instead of the chemical gas release described above, (micro)pore formation can also be carried out by introducing a gas (preferably compressed under pressure). Examples include _CO2 , _N2 , and _SO2 . Gas, which may be liquid and compressed under pressure, can be passed through the extruder, for example via a hose. Gas flow rate can be adjusted by solenoid valves and flow meters. The gas is preferably added in a range from 0.05% to 5%, based on the total weight of the raw materials metered into the extruder.

By using pre-treatment steps, the flexibility of the process can be significantly increased. Therefore, the residence time of the protein matrix in the process can be influenced. The residence time in the pretreatment can be in the range from 3 seconds to 600 seconds, preferably in the range from 3 seconds to 60 seconds, particularly preferably in the range from 5 seconds to 15 seconds.

An exemplary recipe for making meat replicas using salts and acids is as follows.

For example, one of the following recipes can be used to produce a meat imitation by introducing a gas.

The water content in the final product is advantageously greater than 30%, preferably in the range 30% to 70%.

The invention will now be described with reference to non-limiting drawings and examples.

FIG. 2 is a comparison of the color appearance of a product manufactured according to the invention with a conventionally manufactured product (no foaming) and a reference sample (chicken breast); Figure 2 is a comparison of the fibrous structure of a product produced according to the invention with a conventionally produced product (no foam) and a reference sample (chicken breast); FIG. 2 is a comparison of porosity between products made according to the present invention and conventionally made products (no foaming). FIG. 2 is a comparison of porosity between products made according to the present invention and conventionally made products (no foaming). Figure 3 is a further comparison of porosity between products made according to the invention and conventionally made products (no foaming). Figure 3 is a further comparison of porosity between products made according to the invention and conventionally made products (no foaming). FIG. 2 is a comparison of texture values between a product manufactured according to the present invention and a conventionally manufactured product (without foaming); FIG. 3 is a comparison of anisotropy index values between a product manufactured according to the present invention and a conventionally manufactured product (without foaming). FIG. 3 is a comparison of the appearance of products manufactured according to the invention at different gas injection rates; FIG. 3 is a comparison of the appearance of products manufactured according to the invention at different gas injection rates; FIG. 3 is a comparison of the appearance of products manufactured according to the invention at different gas injection rates; FIG. 3 is a comparison of texture values of products manufactured according to the invention; FIG. 2 is an illustration of varying texture profiles of commercially available snack products. FIG. 3 is an illustration of the varying texture profile of a foamed product according to the invention; 1 is a microscopic image of the porosity of a product made according to the present invention. 1 is a microscopic image of the porosity of a product made according to the present invention.

Example 1
In a Buehler 30 mm twin screw extruder with an additional gas supply unit (on the penultimate barrel segment before the cooling die) and a kneading/mixing element in the position of the gas supply unit, the following raw materials were , 145°C, 380 rpm, and a cooling die temperature of 60°C.

The throughput was 30 kg/h. 23 g/min of N ₂ with a pressure of 15-30 bar was introduced into the extrudate.

The produced protein-containing food product has 100% overrun at the die exit (i.e., the height exceeds the height of the extruder exit, thus expanding the sample volume) and is After cooling to room temperature, it shrunk to 30-60% overrun. The protein-containing foamed food product thus produced had very uniformly distributed pores with diameters of approximately 0.1-0.3 mm with a narrow size distribution.

Example 2 (comparison)
Example 1 was repeated except that no nitrogen was introduced into the extrudate.

Color Measurements The products from Examples 1 and 2 were measured at SCI (including specular reflection) using a conventional spectrophotometer. The sample to be measured had a layer thickness such that there was no transmission of light through the sample material and the measuring port was completely covered with the sample material. Reflection measurements were performed in daylight (D65) using a d/8° measurement geometry. L ^* , a ^* , b ^* , and C ^* values were determined. These results are shown in Table 1 below.

The extrudate according to Comparative Example 2 had the lowest L ^* value of 55.61 and was therefore the darkest of all samples. The inventive extrudate according to Example 1 had an L ^* value of 71.06, thus approaching the L ^* value of the reference sample (chicken breast of 79.66).

The extrudate according to comparative example 2 also had the highest red content of 11.10, while the proportion in the inventive extrudate according to example 1 was lower at 7.22. The a ^* value of 1.53 in the reference sample (chicken breast) indicates a very slight reddish tinge in the sample.

The yellowness, expressed by the b ^* value, was relatively the same for the extrudates according to Comparative Example 2 and the inventive extrudates according to Example 1 (26.55 and 27.75, respectively). Chicken breast as a reference had a b ^* value of 13.96.

The C ^* value represents the saturation and can be calculated from the a ^* and b ^* values. This was similar for the extrudates according to comparative example 2 and the inventive extrudates according to example 1 (28.77 for example 2 and 26.74 for example 1). The saturation of chicken breast was lower at 14.04.

Figure 1 shows the differences in these colors. Figure 1 shows on the left the product produced according to Comparative Example 2, in the middle the product of the invention produced according to Example 1 and on the right the reference sample (chicken breast). It can be seen that the sample according to Example 1 is much closer in appearance to the reference sample.

Fibrous Structure Fibrous structure describes the difference in muscle fiber structure of a piece of meat (here chicken breast as a reference sample) compared to the fibrous structure achieved by thermal texturing of plant proteins. is intended. For this purpose, the extrudates according to Examples 1 and 2 were torn open and the internal structure was analyzed macroscopically and microscopically. The results are shown in FIG.

The product produced by Comparative Example 2 was clearly layered and the inner core was straight in length. Around it were placed layer after layer. This reflects the shear forces applied to the material in the process and die. These layers remained relatively dense due to the high water content of the sample. However, as soon as the product produced according to Comparative Example 2 was dried in air, the individual layers were clearly separated from each other.

The product of the invention produced according to Example 1 had a structure similar to that of the product produced according to Comparative Example 2 with respect to the longitudinally oriented layers. However, there was no inner core, only a cavity. A layer was then placed around this cavity by shear forces. In this sample, these layers were not very closely spaced with each other, but were interrupted by small cavities. This resulted in a porous structure. As soon as the product of the invention produced according to Example 1 began to dry, not only the individual layers became more clearly discernible, but also a porous structure and crosslinking resulted. The individual layers were no longer separated from each other, but were connected to each other at certain points. The fibrous structures of the two textured samples were oriented in the longitudinal direction, corresponding to the die, during the thermal process. The reference sample, chicken breast, is visibly denser and more intricately networked.

Porosity Thin sections of each sample were prepared and transmitted light generated contrast between the sample and the pores. Images were recorded and processed using a KEYENCE VHX6'000 digital microscope. The results are shown in Figures 3a) and 3b).

It can be seen that the porosity was very pronounced in the product of the invention produced according to Example 1, thus also ensuring structural cohesion in the dry state. Individual cavities were closed and evenly distributed, with cavities at the outer edges smaller. The closer to the center, the larger the cavity. The mean area of the cavities was 21,292±36,110 ^μm2 , and the mean minimum and maximum diameters were 125±73 ^μm2 or 239±153 ^μm2 . These results are summarized in Table 2.

The product produced according to Comparative Example 2 had only a slightly irregular porous structure. Almost no porosity was observed in the outer region, and cavities were observed in the inner region. These are due to the layered arrangement during the process and also emphasize the statement that the individual layers are not very strongly networked with each other and are relatively quickly detached from each other after water loss. .

Texture The maximum force (peak force) required to break the structure of the products according to Examples 1 and 2 when cutting or biting was determined using a Warnzer-Brazler blade set with a "V" slotted blade. (https://textureanalysis-professionals.blogspot.com/2014/12/texture-analysis-in-action-blade-set.html). This analysis helps quantify the cutting or crisping characteristics of the product. All texture analysis measurements were performed at room temperature of 25°C.

The extruded samples were cut into 30 mm x 30 mm square pieces as part of sample preparation for texture analysis. The samples produced according to Examples 1 and 2 with a thickness of 13-16 mm (Example 1) and 10 mm (Example 2) are cut in the transverse direction (at right angles to the flow direction of the extruded strands) (F _T ). It was also cut parallel (F _L ) to the flow direction of the extruded strand, and the maximum force (peak force) of each was determined and expressed in Newtons (N). All measurements were performed in triplicate.

The cutting speed was set at 50 mm/min, and the cutting distance was 40 mm. These results are shown in Figure 4a.

It can be seen that the product of the invention according to Example 1 has higher strength in both directions of cutting (F _T and F _L ) compared to the product of Comparative Example 2.

Figure 4b shows the anisotropy index of both samples, which can be calculated from the ratio of F _T and F _L values (A=F _T /F _L ); Represents a measure of the fibrous nature of a product. The values for the product of the invention according to Example 1 are significantly reduced compared to the values for the product of Comparative Example 2, which indicates that the fibrous nature of the product of the invention according to Example 1 is increased. is presenting.

The anisotropy index for meat products such as chicken or beef was close to 1 and ranged from 1.1 to 1.75, while for fish meat the anisotropy index was 4.95, which was indicates that there is a large variation in the texture of fish meat in the vertical and horizontal directions.

The dough has no significant anisotropy with respect to F _T and F _L values.
The texture profile for the meat analog was compared to the extruded foamed snack product and the differences in texture were compared to the smoother texture profile of the meat substitute (Figure 5b) and the varying snack product "knusperbrot" (Figure 5a). ) was confirmed by the texture profile. This is due to the fundamental difference in the texture of the "knusperbrot" which has multiple force peaks when the blade penetrates the sample due to its crunchy feel.

Example 3
The following raw materials were processed at temperatures up to 152° C. and screw speeds of 400 rpm in a Buehler 42 mm twin screw extruder with an additional gas supply unit.

Pea protein isolate 43.2%
Pea fiber 8.8%
Water 47.5%
Oil 0.5%.

The gas injection rate into the extruder was kept at a rate of 0 g/h, 35 g/h, 52 g/h, and 70 g/h in four different tests. The total throughput at the exit of the cooling die was 35 Kg/h.

Texture (a) Analysis of Meat Substitute Texture analysis was performed on samples manufactured as in Example 3. FIG. 5 represents a comparison of samples made at three levels of gas injection rate. The maximum force (peak force) required to cut the structure of the product of Example 3 was determined using a 1 mm thick Warner Bratzler Blade Set. This analysis helps quantify the cutting or crisping characteristics of the product. All texture analysis measurements were performed at room temperature of 25°C.

The extruded samples produced according to Example 3 were cut into 20 mm x 20 mm square pieces as part of sample preparation for texture analysis. The sample is then cut not only transversely (perpendicular to the flow direction of the extruded strands) (F _T ), but also parallel to the flow direction of the extruded strands (F _L ), respectively. The maximum force (peak force) was determined and expressed in MPa. Six repetitions were performed for each cutting direction. These results are shown in FIG.

The ratio of the cutting forces in both directions was calculated and expressed as the anisotropy index (A=F _T /F _L ). The A values for foamed products with gas injection rates above 0 g/h were between 1.1 and 1.5, while this value for non-foamed products was closer to 1.

(b) Analysis of Meat Products For comparison, a Warner Blatzer blade with a "rectangular" slotted blade (HDP/WBR) and a thickness of 1.016 mm was used to analyze commercially available chicken, beef, and fish meat products. Performed texture analysis of the product. The cutting speed of the Warner-Bratzler blade was set at 1 mm/sec and the blade penetrated the sample. Samples were measured at 25°C. A total of three replicates were measured for each sample.

The average maximum force for these meat and fish products was found to range from 45.0 to 175.1 N in the transverse direction and 10.0 to 99.9 N in the longitudinal direction.

The anisotropy index for meat products such as chicken or beef was close to 1 and ranged from 1.1 to 1.75, while for fish meat the anisotropy index was 4.95, which was indicates that there is a large variation in the texture of fish meat in the vertical and horizontal directions.

The texture profile for the meat analog was compared to the extruded foamed snack product and the differences in texture were compared to the smoother texture profile of the meat substitute (Figure 7b) and the varying snack product "knusperbrot" (Figure 7a). ) was confirmed by the texture profile. This is due to the fundamental difference in the texture of the "knusperbrot" which has multiple force peaks when the blade penetrates the sample due to its crunchy feel.

In Figures 8a and b microscopic images of the porosity of the product produced according to Example 3 are shown. Optical microscopy (20x) images of the foamed product of Example 3 with a gas injection rate of 70 g/h show that interconnected pores are present inside the foamed product.

Claims (17)

a) metering raw materials into the extruder, wherein at least one raw material is a protein, preferably a vegetable protein, an insect protein, a cellular protein, in particular a cellular protein such as yeast, bacteria, microalgae, molds, etc. , or a mixture of different proteins, wherein the protein content in the dry raw material is more than 50%, particularly preferably in the range from 60% to 90%, and the starch content in said dry raw material is less than or equal to 50%, preferably is in the range of 5 to 30%, and said raw material comprises at least one component having a fiber content;
b) mixing the raw materials in the extruder to produce a mixture;
c) extruding said mixture to produce an extrudate, the solids content of said extrudate being in the range 20% to 60%, preferably in the range 30% to 50%;
d) drawing the extrudate from the extruder through a cooling die while cooling the extrudate to a temperature below 100°C. A foamed product is obtained having a protein content in the range of ~30% by weight, preferably 19-23% by weight, and a liquid content, preferably water content, of 45-70% by weight, preferably 55-65% by weight. controlled pore formation is carried out in said extruder by supplying a gas to
A method characterized in that the foamed product has distributed pores with a diameter of about 0.1 to 1 mm with a narrow size distribution . Method according to claim 1, characterized in that the gas is supplied to the extruder by introducing the gas into the extruder. 3. Method according to claim 1 or 2, characterized in that the gas is selected from the group consisting of _CO2 , _N2 , _N2O or _SO2 . 4. The extruder according to claim 3, characterized in that the gas is introduced into the extruder in an amount of 0.01 to 5% by weight, relative to the total weight of the raw materials metered in step a). Method. Any of claims 1 to 4, characterized in that the specific mechanical energy input introduced by the extruder is in the range from 10 Wh/kg to 120 Wh/kg, preferably in the range from 15 Wh/kg to 30 Wh/kg. or the method described in paragraph 1. The extruder according to claims 1 to 5, characterized in that the temperature inside the extruder is set in the range of 80°C to 180°C, preferably in the range of 120°C to 170°C, particularly preferably in the range of 130 to 160°C. The method described in any one of the above. Oil is injected into the distribution body of the extruder and/or into the cooling die itself, preferably in a proportion ranging from 1% to 10%, relative to the total weight of all raw materials metered into the extruder. 7. Method according to any one of claims 1 to 6, characterized in that: 8. A method according to any one of claims 1 to 7, characterized in that the foamed product has distributed closed cavities . The foamed product has a strength in the longitudinal direction (F _L ) of 10 to 50 N, preferably 15 to 40 N, more preferably 12 to 20 N, and in the transverse direction (F _T ) of 10 to 90 N, preferably 15 to 70 N. 9. A method according to any one of claims 1 to 8, characterized in that it has a maximum force of , more preferably in the range from 15 to 50N. Protein-containing foamed food obtainable by the method according to any one of claims 1 to 9, having a protein content in the range 15-30% by weight, preferably 19-23% by weight, and 45% by weight. Protein-containing foamed food product, characterized in that it has a liquid content, preferably water content, of ~70% by weight, preferably 55-65% by weight. Protein-containing foamed food according to claim 10, characterized in that it is a meat substitute product. 12. Protein-containing foam food according to claim 11, characterized in that the L ^* value of the protein-containing foam food deviates from the L ^* value of the meat product by no more than 20%, preferably by no more than 15%. The protein-containing foamed food has a fibrous, porous, longitudinally oriented cross-linked structure, preferably from 10 to 50 N, preferably from 15 to 40 N, in the longitudinal direction (F _L ). According to claim 12, characterized in that it exhibits a maximum force preferably in the range 12-20N and in the transverse direction (F _T ) in the range 10-90N, preferably 15-70N, more preferably 15-50N. Protein-containing effervescent food as described. The protein-containing foamed food product preferably has a porous structure with distributed pores with a narrow size distribution of about 0.1 to 1 mm in diameter and distributed interconnected closed cavities, the cavities preferably having Protein-containing foamed food according to any one of claims 10 to 13, characterized in that the protein-containing foamed food has a diameter of 100 to 300 μm with a normal deviation in the range of 50 to 70%. The protein-containing foamed food is characterized in that it is a food containing at least one vegetable protein, insect protein, cellular protein, such as yeast, bacteria, microalgae, mold, etc., or a mixture of different proteins. The protein-containing foamed food according to any one of claims 10 to 14. 16. Use of a protein-containing foamed food product according to any one of claims 10 to 15 as a base for cell culture. Extrusion for producing a protein-containing foamed food product by the method according to any one of claims 1 to 9, comprising a gas supply unit and a kneading and/or mixing element located at the gas supply unit. Machine use.

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